Microwave ovens are generally made with front opening doors and such doors having hinges at one side are susceptible to sagging and the accumulation of food residue on the surface of the door seals leading to leakage of microwave energy. This has prompted the Food and Drug Administration to require microwave oven manufacturers to advise the consumer to take certain precautions relative to the hinged front opening oven door to avoid exposure to excessive microwave energy. This warning to the public may be one reason that usage of microwave ovens is not universally accepted. This invention eliminates the problems that make the warning necessary. Microwave ovens with doors that open at the top are shown in Levinson, U.S. Pat. Nos. 3,451,401 and in Kusunoki et al., U.S. 4,019,009 (FIGS. 17 and 18). In these ovens the doors are hinged and pivot upwardly to open. Also, U.S. 3,745,291 (Peterson et al.) and 3,867,606 (Peterson) disclose microwave ovens for treating tires in which the oven is provided with a hinged door at the top and in which the tire after treatment can be elevated. U.S. 3,440,385 of Smith discloses a microwave oven with a front opening door in which the door slides on a pair of guides to pull the treated material out of the oven as the door is opened.